lecture 18 Flashcards
abdominal wall and gluteal region
what are the three functions of the abdomen?
protection, breathing, pressure
what comprises the borders of the abdominal wall?
muscle and bone
name the borders of the abdomen
anterolateral
superior
inferior
posterior
what comprises the anterolateral wall?
musculoaponeurotic walls
what comprises the superior wall?
diaphragm
what comprises the inferior wall?
pelvic inlet (internally) and the superior margin of the lower limb (superficially)
what comprises the posterior wall?
the lumbar vertebrae, lower ribs and muscle
what do we mean by muscluoaponeurotic walls?
muscles of the belly laterally and as they move medially they turn into an aponeurosis (tissue that part of muscle belly and becomes a fibrous tissue to the distal attachment site of that muscle)
what supports the anterolateral musculoaponeurotic walls?
two bony rings and the vertebral column, the two bony rings being the inferior margin of the thoracic skeleton and pelvic girdle
name and describe the layers of the abdominal wall
Skin
Superficial fatty layer called camper fascia
Deep membraneous layer called scarpa’s fascia
Three flat muscles in the anterior abdominal wall: External abdominal oblique, internal oblique, then transversus abdominis
Endoabdominal fascia or transversalis fascia
Extraperitoneal fat coveing viscera of abdomen
Parietal peritoneum once pierced you are in the perotineal cavity and abdominal organs
what is significant about the superficial fascia?
a major site of fat storage
what are the layers of the superficial fascia we talked about in class?
superficial fatty layer (camper’s fascia)
deeper membranous layer (scrapa’s fascia)
what are the two groups of muscles that comprise the anterolateral muscles? what are the innervations for both these groups of muscles?
flat muscles and vertical muscles; thoracoabdominal nerves
what are the muscles in the flat group of muscles within the Anterolateral muscles?
external oblique
internal oblique
transversus oblique
what are the muscles in the vertical group of muscles within the Anterolateral muscles?
rectus abdominis adn pyramidalis
which of the flat muscles are the largest and most superficial?
the external obliques and the direction of these fibers move like “hands in pockets”
what are the directions of the fiber movement in flat muscles?
perpendicular to external oblique
what are the deepest of the flat muscles and how do these muscle fibers run?
tranversus abdominis; the fibers run horizontally
what is the name of the sheath enclosing the two vertical muscles formed by aponeurosis of the flat muscles?
rectus sheath
what causes the separation of the rectus abdominis?
linea alba
this muscle is a small triangular muscle, it tenses the linea alba, and is absent in 20% of the population
pyramidalis
what are the two nerves we discussed in class that arise from the L1 dermotome that is comprised of other nerves?
Iliohypogastric nerve
Ilioguinal nerve
what are dermatomes?
the nerves that leave the spinal column
what is the linea alba?
a fibrous band which runs vertically the entire length of the anterior abdominal wall and can be seen as a groove in the skin in people with less body fat in that area
the gluteal region is physically part of the _____, but functionally part of the _____?
trunk; lower limb
what is the gluteal region comprised of?
muscle and thick superficial fascia
what are the boundaries of the gluteal region?
iliac crest superiorly and gluteal fold inferiorly
name the gluteal ligaments?
Sacro-Iliac ligament is sacrum to the ilium
Sacrotuberous ligament – goes from sacrum to the ischial tuberosity
Sacrospinous ligament - goes from sacrum to the ischial spine
what are the layers of muscles of the gluteal region divided into?
superficial and deep layer, where the superficial layers are large muscles and the deep layers are small layers
what comprises the superficial layers of the gluteal region?
two groups:
1) three overlapping glutei (maximus, medium and minimum)
2) tensor fascia latae
describe in terms of locomotion, the muscles of the gluteal region?
extensors, abductors, medial rotators of the thigh
what is the most superficial, largest, and heaviest muscle of the body?
gluteus maximus
these gluteal muscles are smaller and fan shaped
gluteus medius and gluteus minimus
this muscle is enclosed between two layers of fascia lata?
Tensor fasciae latae
what are the muscles in the deep layer of the gluteal region?
Piriformis
obturator internus
superior and inferior gemelli
quadratus femoris
what are the main movements of these deep gluteal muscles?
These muscles are lateral rotators of thigh and also help stabilize the hip joint
what is significant about the piriformis?
A key landmark of the gluteal region, it determines the names of the blood vessels and nerves, ie
Superior gluteal vessels and nerves emerge superior to it
Inferior gluteal vessels and nerves emerge inferior to it
what deep muscles form the triceps coxae?
Obturator internus and superior and inferior gemelli and these occupy the gap between the piroformis and quadratus femoris
what deep muscle leaves through the lesser sciatic foramen?
obturator foramen
what happens when the there is injury to the superior gluteal nerve?
Results in motor loss, disabling the gluteus medius resulting in a limp
what is the positive trendelenberg test?
pelvis drops to contralateral side, injury to superior gluteal nerve
what happens when the sciatic nerve is injured?
Typically due to compression of the sciatic nerve by the piriformis muscle (piriformis syndrome)
Seen in athletes where there is excessive use of the gluteal muscles and in women
what percent of the population is affected when the common fibular division passes through the piriformis causing nerve compression?
12% of the population
where can we give intragluteal injections?
the superolateral quadrant of the buttocks
superior to a line extending from the PSIS to the superior border of the greater trochanter
Can also be given to the anterolateral part of the thigh
why are intragluteal injections the common site for IM injections?
because the muscles are thick and large allowing absorption by the intramuscular veins
how should you place your hands when giving an injection in the anterolateral part of the thigh?
the index finger is placed on the ASIS and the fingers spread posteriorly along the iliac crest until the middle finger feels the tubercle of the iliac crest
Both sites are superior to the sciatic neve.
what is the syndrome called when the sciatic nerve pierces the piriformis and compresses it?
piriformis syndrome
what is the muscle that sits between the superior and inferior gemellus?
obturator internus
